The present invention relates to a water-based fiber treatment agent. More particularly, the present invention relates to a water-based fiber treatment agent that can equip fibers with such properties as an excellent smoothness and lubricity, a reduced tack, and an appropriate slickness.
Silicone oils are characterized by an excellent heat resistance, excellent water repellency, and excellent smoothness and as a consequence are used as lubricants for unprocessed yarns and raw cotton, as spinning lubricants, as softness finishing agents for knitted and woven fabrics, and as color-deepening agents for polyester fiber woven fabrics. As examples in this regard, polydimethylsiloxanes are used as fiber treatment agents that impart smoothness and lubricity to fibers while amino-functional polyorganosiloxanes are used as fiber treatment agents that impart a slick feel to fibers.
The preceding notwithstanding, various problems have been associated with the use of the above-described fiber treatment agents. Thus, fiber treatment agents comprising polydimethylsiloxane are unable to equip fibers with a satisfactory smoothness, lubricity, or resistance to adhesion. Fiber treatment agents comprising amino-functional polyorganosiloxane cause fibers to have a very slick feel and are unable to improve the handle so as to provide an excellent softness while exhibiting a dry sensation. Moreover, while amino-functional polyorganosiloxane is used as a color-deepening treatment agent for, for example, the georgette fabric (dyed black) produced from strongly twisted polyester filament yarn, it also causes the fiber to have a very slick feel and ultimately causes a deterioration in the sense of dryness to the touch.
An object of the present invention is to provide a water-based fiber treatment agent that has the ability to equip fibers with such properties as an excellent smoothness and lubricity, a reduced tack, and an appropriate or moderate slickness.
The present invention relates to a water-based fiber treatment agent comprising
(A) about 100 weight parts silicone oil,
(B) about 5 to 200 weight parts silicone rubber powder with an average particle size of 0.1 to 500 xcexcm, and
(C) a freely selected amount of water.
The water-based fiber treatment agent according to the present invention will be explained in detail hereinbelow.
The water-based fiber treatment agent according to the present invention comprises (A) silicone oil, (B) silicone rubber powder with an average particle size of 0.1 to 500 xcexcm, and (C) water. The silicone oils typically employed for fiber treatment agents can be used as component (A), but otherwise the viscosity, molecular structure, and silicon-bonded groups in component (A) are not critical. Component (A) preferably has a viscosity of 10 to 100,000 mPaxc2x7s at 25xc2x0 C. and a straight-chain or partially branched straight-chain molecular structure. The degree of polymerization of this component is not critical, but preferably is in the range from 2 to 2,000. This component has a degree of polymerization preferably from 2 to 100 when the treatment agent will be used as a lubricant and preferably from 100 to 2,000 when the treatment agent will be used for the purpose of improving the handle. Component (A) can be hydrophilic or hydrophobic. When (A) is hydrophilic, an emulsifying agent can be used on an optional basis to effect dispersion of (A) in the water; when (A) is water-soluble there is no absolute requirement for use of an emulsifying agent; and when (A) is hydrophobic the use of an emulsifying agent is preferred in order to effect a highly stable dispersion of (A) in water.
Component (A) can be exemplified by trimethylsiloxy-endblocked polydimethylsiloxane such as 
and silanol-endblocked polydimethylsiloxane such as 
by silicone oils as afforded by replacing all or part of the methyl in the preceding polydimethylsiloxanes with non-methyl alkyl such as ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, or dodecyl; alkenyl such as vinyl, allyl, or hexenyl; cycloalkyl such as cyclopentyl or cyclohexyl; or aryl such as phenyl, tolyl, or naphthyl; for example, dimethylsiloxane-methylphenylsiloxane copolymer such as 
and dimethylsiloxane-methylvinylsiloxane copolymer such as 
by silicone oils as afforded by replacing part of the methyl in the preceding polydimethylsiloxanes with the hydrogen atom, for example, polymethylhydrogensiloxane such as 
and by silicone oils as afforded by replacing part of the methyl in the preceding polydimethylsiloxanes with alkoxy such as methoxy, ethoxy, or propoxy; haloalkyl such as 3,3,3-trifluoropropyl; an amino-functional organic group such as 3-aminopropyl, N-(2-aminoethyl)-3-aminopropyl, or N-cyclohexyl-3-aminopropyl; an epoxy-functional organic group such as 3-glycidoxypropyl or 2-(3,4-epoxycyclohexyl)ethyl; a mercapto group such as 3-mercaptopropyl; an acrylic-functional organic group such as 3-methacryloxypropyl; the carboxyl group; the amide group; or a polyether group; for example, silicone oils such as 
The silicone rubber powder used as component (B) functions to impart smoothness and lubricity to fibers and to reduce their tack. Neither of these functions can be satisfactorily fulfilled by a water-based fiber treatment agent composed of only component (A) and water. And, in the particular case of use of an amino-functional polyorganosiloxane as the silicone oil, component (B) imparts an appropriate or acceptable slickness to the fiber. The average particle size of component (B) should be in the range from 0.1 to 500 xcexcm. The preferred range for the average particle size is 0.5 to 50 xcexcm because this range provides the instant treatment agent with a particularly good blending stability, dilution stability, and shear stability. With regard to shape, component (B) can be spherical, disk-like, or irregular in shape with a spherical shape being preferred.
Component (B) is preferably silicone rubber powder as produced by curing a silicone rubber composition while the composition is dispersed in a microparticulate state in water. The silicone rubber composition used for this purpose can be exemplified by addition-curing silicone rubber compositions, condensation-curing silicone rubber compositions, organoperoxide-curing silicone rubber compositions, and ultraviolet-curing silicone rubber compositions. In a particularly preferred embodiment, component (B) is produced by the cure of a silicone rubber composition while the composition is emulsified in water using an emulsifying agent. In an even more preferred embodiment, component (B) is produced by the cure of an addition-curing silicone rubber composition or a condensation-curing silicone rubber composition while the composition is emulsified in water using an emulsifying agent. The addition-curing silicone rubber compositions can be exemplified by compositions comprising organopolysiloxane bearing at least 2 alkenyl groups in each molecule, organopolysiloxane bearing at least 2 silicon-bonded hydrogen atoms in each molecule, and platinum catalyst. The condensation-curing silicone rubber compositions can be exemplified by compositions comprising organopolysiloxane bearing at least 2 silicon-bonded hydroxyl groups or hydrolyzable groups (e.g., alkoxy, oxime, acetoxy, or aminoxy) in each molecule, silane crosslinker bearing at least 3 hydrolyzable groups (e.g., alkoxy, oxime, acetoxy, or aminoxy) on the silicon atom in each molecule, and a condensation catalyst such as an organotin compound or an organotitanium compound. Additional improvements in fiber smoothness and lubricity can be had through the use of a water-based fiber treatment agent that employs silicone rubber powder prepared from the blend of noncrosslinking oil with a silicone rubber composition as described above. This noncrosslinking oil is an oil that is simply present in the silicone rubber powder in a form that can spontaneously bleed from the powder or can be extracted therefrom by organic solvent. Oils of this type can be exemplified by noncrosslinking silicone oils and noncrosslinking organic oils. Noncrosslinking silicone oils are silicone oils that do not participate in the curing reaction that forms the silicone rubber powder and can be specifically exemplified by nonreactive silicone oils such as trimethylsiloxy-endblocked dimethylpolysiloxanes, trimethylsiloxy-endblocked dimethylsiloxane-methylphenylsiloxane copolymers, and trimethylsiloxy-endblocked dimethylsiloxane-methyl(3,3,3-trifluoropropyl)siloxane copolymers.
Component (B) is added to the treatment agent under consideration generally at from 5 to 200 weight parts, preferably at from 5 to 150 weight parts, more preferably at from 5 to 100 weight parts, and particularly preferably at from 10 to 100 weight parts, in each case per 100 weight parts component (A). When component (B) is used in an amount below the specified lower limit, the corresponding water-based treatment agent will be unable to satisfactorily improve fiber smoothness and lubricity or lower the tack, or prevent the tendency for a strong slickness to appear. Use of component (B) in an amount exceeding the specified upper limit is associated with a variety of problems. For example, when such a water-based treatment agent is used as a yarn lubricant, component (B) will accumulate as a scummy residue on the yarn guides. In another context, whitening phenomena (pale white color) tend to be produced when such a water-based treatment agent is used as a color-deepening agent for polyester fabrics.
The treatment agent according to the present invention comprises component (A), component (B), and water. The use of an emulsifying agent is not absolutely required when component (A) is hydrophilic, but is preferred in order to effect the stable dispersion of component (B) in water. When component (A) is hydrophobic, the use of emulsifying agent is preferred in order to effect the stable dispersion of both components (A) and (B) in water. The subject emulsifying agents can be exemplified by cationic emulsifying agents, nonionic emulsifying agents, and anionic emulsifying agents with nonionic emulsifying agents being preferred. The cationic emulsifying agents can be specifically exemplified by quaternary ammonium hydroxides and their salts such as octyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octyldimethylbenzylammonium hydroxide, decyldimethylbenzylammonium hydroxide, didodecyldimethylammonium hydroxide, dioctadecyldimethylammonium hydroxide, beef tallow trimethylammonium hydroxide, and cocotrimethylammonium hydroxide. The nonionic emulsifying agents can be exemplified by polyoxyalkylene alkyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylenealkylsorbitan alkyl esters, polyethylene glycol, polypropylene glycol, and diethylene glycol. The anionic emulsifying agents can be exemplified by alkylbenzenesulfonates, alkylsulfonates, the salts of alkyl sulfate esters, the salts of the sulfate esters of polyoxyalkylene alkyl ethers, the salts of the sulfate esters of polyoxyalkylene alkylphenyl ethers, and the salts of alkyl fatty acids.
The emulsifying agent is preferably used at from 5 to 100 weight parts for each 100 weight parts of the total of components (A) and (B). The water may be used in any amount and its quantity of addition is thus not critical. However, when viewed from the standpoint of the efficiency of fiber treatment, the water is preferably used at from 50 to 400 weight parts for each 100 weight parts of the total of components (A) and (B).
The dispersion of component (A) in water can as a general matter be formed using, for example, a stirrer, homomixer, line mixer, colloid mill, or homogenizer. An emulsifying agent and particularly a nonionic emulsifying agent as described above is preferably used during this step in order to improve the stability of component (A) in water. A polyorganosiloxane (A) that contains about 2 mole % amino-functional organic group or carboxy-functional organic group in the molecule can be dispersed in water as liquid droplets with an average particle size of 0.01 to 0.1 xcexcm using only an ordinary stirrer and without the use of a special emulsifying device. The use of an emulsifying device such as a colloid mill or homogenizer is preferred with other organopolysiloxanes, and in these cases the average particle size of the liquid droplets will generally be from 2 to 10 xcexcm. The average particle size produced by dispersing a cyclic diorganosiloxane in water with an emulsifying device such as an homogenizer and then polymerizing the cyclic diorganosiloxane will ordinarily be from 0.2 to 5 xcexcm.
The mechanical dispersion of component (B) in water can, for example, be used to effect dispersion of the silicone rubber powder (B) in water. However, the dispersion of component (B) is preferably produced by curing a silicone rubber composition, e.g., an addition-curing, condensation-curing, organoperoxide-curing, or UV-curing silicone rubber composition, while the composition is dispersed in a microparticulate state in water. A particularly preferred method for effecting the dispersion of (B) in water comprises curing the silicone rubber composition while it is emulsified in water in the presence of an emulsifying agent. The treatment agent according to the present invention is preferably prepared by intermixing a water-based dispersion of component (A) with a water-based dispersion of component (B) and particularly a water-based dispersion of component (B) as afforded by curing a silicone rubber composition while the composition is emulsified in water in the presence of an emulsifying agent. In order to improve the stability of component (B) in water, the water-based dispersion of component (B) is preferably produced using an emulsifying agent as described above and in particular using a nonionic emulsifying agent.
Other components can be admixed into the treatment agent according to the present invention on an optional basis, for example, antistatics, charge-controlling agents, preservatives, and rust inhibitors. In addition, component (A) can be crosslinked and the treatment efficiency with the subject treatment agent can be improved by the admixture of a tin condensation catalyst, e.g., dibutyltin diacetate or dibutyltin dilaurate, or a zinc- or zirconium-based condensation catalyst.
The treatment agent according to the present invention can be used on, for example, regenerated fibers such as rayon, semisynthetic fibers such as acetate; and synthetic fibers such as nylon, polyester, and acrylic fibers. This treatment agent can be used to impart smoothness and lubricity to such fibers. For example, it can be used as a lubricant for raw yarn and raw cotton, as a treatment agent for cotton wadding, as a lubricant for the nylon staple fiber for mixture with wool, as a lubricant for acrylic staple fiber, as a knitting lubricant, as a spinning lubricant, and as a lubricant for machine thread (elastic urethane yarn). When component (A) is silicone oil containing amino-, epoxy-, amide-, or carboxyl-functional organic groups, the treatment agent can be used as a fabric finishing agent. In specific terms, a treatment agent of this type can be used as a napping agent for napped fabrics; as an agent for improving the handle, i.e., for improving the softness, smoothness, compression recovery, wrinkle resistance, and stretch/recovery performance; as a treatment agent for deepening the color (increasing the depth of color) of polyester fabrics; as a dissolution-resistant treatment agent for sportswear and the like; and as a waterproofing agent. Moreover, use of a silicone oil (A) containing polyether-functional organic groups produces a water-based fiber treatment agent that is self-emulsifying even without the admixture therein of an emulsifying agent as described above.
The subject treatment agent can be uniformly adhered, either neat or from its aqueous dilution, on the fabric, yarn, cotton, tow, or top using such coating techniques as spraying, kiss roll coating, or gravure coating. Application is then followed by drying and heat treatment. The treatment agent add-on will generally be from 0.1 to 8 weight % calculated on fiber. Considered on a case-by-case basis, the add-on is generally preferably from 0.2 to 1.0 weight % in the case of raw cotton or raw yarn of polyester, nylon, etc., and preferably from 0.3 to 1.0 weight % when the objective is to improve the handle of knits and weaves that use cotton or polyester/cotton mixed yarn.
The water-based fiber treatment agent according to the present invention will now be explained in greater detail using working examples. The viscosity values reported in the examples were measured at 25xc2x0 C.
A silicone rubber composition was prepared by mixing the following to homogeneity: 96 weight parts dimethylvinylsiloxy-endblocked polydimethylsiloxane (viscosity=400 mPaxc2x7s), 4 weight parts trimethylsiloxy-endblocked polymethylhydrogensiloxane (viscosity=20 mPaxc2x7s), 6 weight parts trimethylsiloxy-endblocked polydimethylsiloxane (viscosity=20 mPaxc2x7s), and isopropanolic chloroplatinic acid solution in an amount sufficient for the solution to provide 20 weight-ppm platinum metal calculated on the dimethylvinylsiloxy-endblocked polydimethylsiloxane. Curing this silicone rubber composition by holding for 1 day at room temperature gave a silicone rubber with a durometer of 28.
This silicone rubber composition was then emulsified in its entirety using 53 weight parts of a 3 weight % aqueous solution of polyoxyethylene nonylphenyl ether (HLB=13.1). This was followed by the addition of 50 weight parts water to afford an aqueous dispersion of the silicone rubber composition. The silicone rubber composition dispersed in the water was then cured by holding the aqueous dispersion for 1 day at room temperature to produce a water-based dispersion of silicone rubber powder (silicone rubber powder content=60 weight %). The silicone rubber powder in this water-based dispersion was spherical and had an average particle size of 4 xcexcm.
158.5 g water, 15 g hexadecyltrimethylammonium chloride, and 150.0 g methyltrimethoxysilane were placed in a 500-mL beaker, mixed to homogeneity, and then converted into a water-based dispersion by a single pass of the mixture through an homogenizer at a pressure of 300 kgf/cm2. 152.7 g water, 10 g hexadecyltrimethylammonium chloride, and 0.8 g sodium hydroxide were subsequently introduced into a 500-mL four-neck flask fitted with a stirrer, reflux condenser, addition funnel, and thermometer and were gradually heated to 85xc2x0 C. while stirring. At this point the already prepared water-based dispersion was gradually added dropwise over 90 minutes from the addition funnel. After the completion of addition, hydrolysis of the methyltrimethoxysilane and condensation were carried out over 30 minutes at 85xc2x0 C. The reaction was followed by the addition of 1.2 g acetic acid to produce the water-based dispersion of a polymethylsilsesquioxane powder (PMS powder) with the average unit formula (CH3SiO3/2) and an average particle size of 0.05 xcexcm.